New analytical techniques were developed and used in enzymatic research and in clinical investigations of lipidoses. The analysis of leukocytes and liver biopsy specimens from a patient with Gaucher's disease and a patient with Niemann Pick disease Type B continues. Both patients received orthotopic liver transplants for treatment of their sphingolipidoses. We are measuring the rate of reaccumulation of glucocerebroside and sphingomyelin, and are studying the post-transplantation changes in glucocerebrosidase and sphingomyelinase. A patient with an unknown storage disorder was studied to determine the nature of the storage process. The patient exhibited multiple xanthomas of the aerodigestive track which were found to be composed primarily of triglyceride, cholesterol esters and cholesterol. Liver biopsy showed elevations of cholesterol, cholesterol ester and bis(monoacylglycerol)phosphate. Gaucher's disease is a lipidosis caused by a deficiency of the lysosomal enzyme, glucocerebrosidase. Significant changes occur in the bone marrow of patients with this disease. A study of the changes in the bone marrow lipids of Gaucher patients caused by disease progression or therapeutic intervention was concluded this year. The results of this study provide a biochemical basis for interpreting bone marrow changes seen by Quantitative Chemical Shift Imaging.